 // comment
 console.log("hello world")
 // 变量
 let name="gavin"
 console.log(name)
 console.log(typeof name)
 let age =  20
 console.log(typeof age)
 // 常量
 const city = '南京'
 console.log(city)

 // object
 person = {
    name:'kevin',
    age: 30
 }
 person.name='二狗'
 person['name']='张三'
 console.log(person)

 // array
 let selectedColors = ['red','blue']
 selectedColors[2]='green'
 console.log(selectedColors)
 console.log(selectedColors[0])


 // function 函数
function greet(){
    console.log('hello world')
}

greet();
